Do you answer every inquiry about your wellbeing with 'I'm fine, just tired'? If so, you've fallen prey to Collective Fatigue Syndrome.

But this is no cry for help. Instead, it's about emphasising how tired you are in order to show that you're in demand and having it all.

According to a report in Grazia magazine, this has come about because of a desire to emulate modern power-women such as Facebook chief Sheryl Sandberg, who live immensely successful lives but never seem to pause to draw breath.

Tired: Women are taking on too much in an attempt to prove they can keep up with the likes of Sheryl Sandberg

In Sandberg's case, she juggles life at the top of one of the world's biggest tech firms with motherhood and a secondary career as an inspirational speaker.

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Not only did she find time to write a book, she's also found a few minutes to write the foreword to another. In short, there's little she can't do.

Inspiration: Sheryl Sandberg agrees that it's time for men to pull their weight at home

The message Sandberg and co give us is that you really can have it all - but you'll have to work extraordinarily hard for it. And yes, that does mean enduring terminal tiredness.

You might need a nanny too, as Sandberg has, to her credit, admitted.

But is it really possible to follow in their super-charged footsteps?

According to Professor Jim Horne, author of Sleepfaring: A Journey Through The Science Of Sleep, women need to disengage from time to time in order to perform at their best.

'On average women need 20 minutes more sleep than men,' the professor told Grazia. 'Because women tend to multi-task, they use more of their actual brain than men do during the day, so their need to go into recovery mode and disengage from the senses is greater.'

But though women's need for sleep is greater, pressure to emulate Sandberg and 'have it all' means most are getting less sleep than ever before - with disastrous results for their health.

'Women are still working what is known as "The Second Shift",' says occupational psychologist Almuth McDowell.

'They're often the ones who have to do the little things - remembering birthdays, paying bills, booking holidays.

'Research shows there are genuine gender differences in who takes care of these tasks within the home.'

A recent survey, which found that women did 70 per cent of chores in the home, would appear to back Dr McDowell's claims.

Among female breadwinners, more than half (55 per cent) say they still do the lion's share of the housework - even if their partner has been at home all day.

Second shift: Dr Almuth McDuwall says women are doing too much in an attempt to have it all

Not surprisingly, the beginnings of a backlash are on the horizon, starting with the new book Getting To 50/50: How Working Parents Can Have It All by a pair of former executives Sharon Meers and Joanna Strober.

The duo say that splitting chores is the key to a happy household - a view shared by Sandberg who penned the introduction to the book.

Nevertheless, female one-upmanship is proving equally problematic for the UK's hordes of sleep deprived women, many of whom are obsessed with keeping up appearances.

'Women are often their own worst enemies because our expectations of ourselves are so high,' adds Dr McDowall.

'It can be useful to think that things don't have to be perfect - just good enough.'

And that means acknowledging that being tired all the time is neither healthy nor a sign that you're having your cake and eating it.